Disorders of the blood present many important health concerns. For example, a decreased hematocrit, e.g. low number of red blood cells, decreased volume of red blood cells, or reduced hemoglobin concentration, is indicative of pathological conditions such as, but not limited to, anemia. The symptoms of anemia may include fatigue, dizziness, headache, chest pain, shortness of breath, and depression.
Treatment of blood disorders such as anemia may involve increasing the patient's hematocrit. One method of treating anemia is to give red blood cell transfusions. This procedure, however, can have risks associated with it. Transfusion reactions may occur if blood is not correctly and completely matched between the donor and the patient, and some diseases, especially viral diseases, may be in the blood being transfused. A theoretical concern, not yet proven, is that frequent blood transfusions may damage the immune system, which protects the body from infections.
Regulatory authorities have approved recombinant human erythropoietin for treatment of anemia associated with chronic renal failure (CRF), anemia related to therapy with AZT (zidovudine) in HIV-infected patients, anemia in patients with non-myeloid malignancies receiving chemotherapy, and anemia in patients undergoing surgery to reduce the need of allogenic blood transfusions.
Due to the serious health problems arising from blood disorders, such as those conditions associated with decreased hematocrit, it is of interest to develop other agents capable of treating these disorders. These agents include, but are not limited to, those that increase hematocrit level.